From 0804815e69cd5e0428c087b5191f7f3f34d9122b Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 2 Nov 2024 10:17:16 +0100
Subject: [PATCH] make char::is_whitespace unstably const

---
 library/core/src/char/methods.rs                       | 5 +++--
 library/core/src/unicode/unicode_data.rs               | 2 +-
 src/tools/unicode-table-generator/src/cascading_map.rs | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/library/core/src/char/methods.rs b/library/core/src/char/methods.rs
index 206bbf5690ef1..8bae1e882fc69 100644
--- a/library/core/src/char/methods.rs
+++ b/library/core/src/char/methods.rs
@@ -320,7 +320,7 @@ impl char {
     /// '1'.is_digit(37);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_char_is_digit", issue = "132241")]
+    #[rustc_const_unstable(feature = "const_char_classify", issue = "132241")]
     #[inline]
     pub const fn is_digit(self, radix: u32) -> bool {
         self.to_digit(radix).is_some()
@@ -856,8 +856,9 @@ impl char {
     /// ```
     #[must_use]
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_char_classify", issue = "132241")]
     #[inline]
-    pub fn is_whitespace(self) -> bool {
+    pub const fn is_whitespace(self) -> bool {
         match self {
             ' ' | '\x09'..='\x0d' => true,
             c => c > '\x7f' && unicode::White_Space(c),
diff --git a/library/core/src/unicode/unicode_data.rs b/library/core/src/unicode/unicode_data.rs
index cba53bf5054e6..261b41aadc579 100644
--- a/library/core/src/unicode/unicode_data.rs
+++ b/library/core/src/unicode/unicode_data.rs
@@ -575,7 +575,7 @@ pub mod white_space {
         0, 0, 0, 0, 0, 0, 0, 0, 0,
     ];
     #[inline]
-    pub fn lookup(c: char) -> bool {
+    pub const fn lookup(c: char) -> bool {
         match c as u32 >> 8 {
             0 => WHITESPACE_MAP[c as usize & 0xff] & 1 != 0,
             22 => c as u32 == 0x1680,
diff --git a/src/tools/unicode-table-generator/src/cascading_map.rs b/src/tools/unicode-table-generator/src/cascading_map.rs
index 036f0bd7eac74..1eb35e819c07c 100644
--- a/src/tools/unicode-table-generator/src/cascading_map.rs
+++ b/src/tools/unicode-table-generator/src/cascading_map.rs
@@ -65,7 +65,7 @@ impl RawEmitter {
         self.bytes_used += 256;
 
         writeln!(&mut self.file, "#[inline]").unwrap();
-        writeln!(&mut self.file, "pub fn lookup(c: char) -> bool {{").unwrap();
+        writeln!(&mut self.file, "pub const fn lookup(c: char) -> bool {{").unwrap();
         writeln!(&mut self.file, "    match c as u32 >> 8 {{").unwrap();
         for arm in arms {
             writeln!(&mut self.file, "        {},", arm).unwrap();